This invention relates generally to connectors and more particularly to connectors for optic fibers.
Connectors for optic fibers have been disclosed in the following U.S. Pat. Nos. 4,097,129 (Wellington et al), No. 4,188,087 (D'Auria et al), No. 4,212,514 (Prunier et al), No. 4,236,787 (Iacono et al), No. 4,320,938 (Gunnersen et al), No. 4,793,607 (Carlsen), No. 4,458,983 (Roberts), No. 4,767,178 (Sasaki et al), No. 4,793,683 (Cannon, Jr. et al), No. 4,807,957 (de Jong et al), No. 4,812,003 (Dambach et al), No. 4,812,006 (Osborn et al), and No. 4,838,640 (Anderton).
In the aforenoted U.S. Pat. No. 4,236,787 (Iacono et al) there is disclosed an optical fiber connector having a pair of sections, each of which is arranged to have the free end of a respective optic fiber extend therethrough. One of the sections includes an elastic compressible, cone having a bore extending therethrough and into which the bare, i.e., uncoated or unjacketed, free ends of both of the optic fibers extend to abut each other to form a light transmissive joint. The other of the sections includes an annulus which is flared outwardly in correspondence to the tapered cone. The two sections are arranged to be threadedly engaged so that cone is received in and radially compressed by the annulus to decrease the inside diameter of its optic fiber holding bore so that the fibers will be axially aligned. In one embodiment of the connector respective compressible sleeves are provided to hold or secure the jackets of the two optic fibers adjacent their bare free ends as the two sections of the connector.
In the aforenoted U.S. Pat. No. 4,097,129 (Wellington et al) there is disclosed another optic fiber connector making use of a compressible body formed of a flexible and resilient molded plastic having a mid-portion including a bore in which the free ends of the optic fibers to be joined are located. A threaded member is mounted on the compressible body to compress the mid-portion so that the optic fibers are aligned in the bore. That connector also includes two additional threaded members for compressing the ends of the body to clamp the jackets of each of the optic fibers adjacent their bare free ends.
While the aforementioned patents to Iacono et al and Wellington et al appear generally suitable for their intended purposes they never the less appear to leave something to be desired from the standpoint of functionality. In this regard the bore in the compressible cone of the Iacono et al patent appears to be almost double the external diameter of the bare optic fiber. The bore in the compressible member of the Wellington et al patent is substantially greater, e.g., 0.0005 to 0.002 inches (0.013 to 0.05 mm) than the outer diameter of the bare optic fiber. The relatively large diameter bores (as compared to the diameter of the bare optic fiber) of those patents, coupled with the soft resilient nature of the compressible members in which those bores are located may permit the free ends of the fibers to misalign or skew by digging into the material contiguous with the bores when the connectors are tightened. Moreover, the compressible members for clamping the jackets of the optical fibers of each of those connectors appear incapable of clamping both loosely buffered cables and tightly buffered cables, since the amount of inward radial movement that they can achieve is too limited. Thus, it is possible that the fibers could slip in each of each of those connectors, thereby resulting in a less-than-optimum light transmissive joint. Further still, since the jacket-clamping threaded members of the Wellington et al patent also act on the body having the optic fiber receiving bore, their tightening could result in undesired stresses or misalignment of the fiber ends within the bore. Further yet, the connector of the Welington et al patent does not permit disconnection while protecting the free (bare) ends of both optic fibers. In this regard if the connector of the Wellington et al patent is disconnected the free ends of at least one of the fibers will have to be removed from the bore in the compressible body, thereby subjecting that end to potential injury.